SU1418526A1 - Device for measuring the tightening force of threaded connection - Google Patents

Abstract

The invention relates to mechanical engineering and can be used in critical threaded connections requiring the provision of a calculated tightening force. The goal is to ensure that the tightening force can be controlled during the tightening process and to simplify the means of indication. The device comprises a hollow body supported on the end of the nut and mounted on the threaded rod of the threaded connection rod. The latter is placed in the casing and is made with blind axle meters and radial holes. An annular cavity between the stem and the housing, filled with a bladder, communicates with the axial bore. When the nut is rotated and the threaded rod is lengthened, the liquid from the annular cavity is forced out into the axial hole of the stem, moving the measuring rod placed in the hole with a scale. (, the degree of protrusion of the measuring rod from the rod characterizes the level of the axial force achieved at this stage of tightening. 2 Il.

Description

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I The invention relates to a machine-building and can be used, mainly in responsible threaded connections | x, requiring settlement effort for-.

 The purpose of the invention is to ensure the possibility of controlling the tightening force during the tightening process and to simplify the means of indication.

i FIG. 1 shows the device, common B1 | d; in fig. 2 is a view A of FIG. one.

I The device contains a stem 2 with an I piston 3 screwed on the free end of the threaded rod 1. The rod 2 is made with a blind o (left hole 4 and channels 5, communicating with the axial hole 4 near the bottom eifo 6. The stem 2 is movably mounted inside - the pH of the hollow body 7. On the stem 2 is fixed the yushka 8, spring-loaded spring 9 to the junction 7. Between the housing 7 and the stem 2, an annular cavity 10 is formed, 31 by means of seals, for example, rubber rings 11 and 12 of the round lobe. The cavity 10 is filled with liquid 18 The display is made in the form of a mobile and The measuring rod 14 with the scale 15 and hermetically (by means of the rubber ring 16) is installed in the axial bore 4 on the side of the lid 8. At the last, the latch 17 of the position of the measuring rod 14 is fixed in the form of a swivel bracket. . On the threaded rod 1, a nut 19 is fitted.

The device works as follows.

: The stem 2, when the cap 8 is rotated, is screwed onto the free end of the threaded rod until it stops against it. Shift the fixation 17 from the groove 18 of the measuring rod. Under the action of the spring 9, the housing 7: moves axially against the stop into the nut 19 of the threaded connection. As a consequence, the volume of the cavity 10 is reduced. In this case, the liquid 13 moves through the channels 5 into the axial hole 4, displaces the measuring rod 14 by some value outwardly relative to the cover 8, and according to the reading on the scale 15 marks the initial position of the measuring rod 14. As the nut 19 is tightened on the threaded rod 1, its rotation with a wrench, the rod 2, together with the threaded rod 1 extended during tightening, moves relative to the nut 19, and the housing 7 contacts the nut 19. The cavity 10 decreases

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The liquid displaces the measuring rod 14 from the axial bore 4 by an amount proportional to the elongation of the threaded rod 1, i.e. proportional to the force achieved at this stage of tightening in the rod 1. The axial movement of the measuring rod 14 is so many times greater than the movement of the rod 1 with the rod many times the cross-sectional area of the cavity 10 is greater than the cross section of the axial bore 4, i.e. The system acts as a power steering. During the tightening process, the position of the measuring rod 14 on the scale 15 is repeatedly monitored, and 1O the torque in the threaded rod is preliminarily removed for the similar threaded connection of the calibration characteristics of the loading of the rod 1. Technological and economic advantages of the proposed device in comparison with the known one are to improve the accuracy of tightening a threaded joint, since the design provides the ability to control the efforts achieved in successive stages of tightening the threaded rod, which eliminates accidental overloading or under-stretching (for example, during swapping and turn the wrench). The quality of the assembly, the reliability of the threaded joint and the machine as a whole are improved. In addition, the device does not require energy sources and the use of measuring devices.

Claims (1)

Invention Formula A device for determining the tightening torque of a threaded joint, comprising a stem with an axial bore that is movably mounted in a hollow body, mounted on a rod and a lid spring-loaded to the housing and indicating means, characterized in that in order to control the tightening force during the thrust process In order to simplify the indication means, the stem at the end opposite to the cover is made with a piston hermetically installed in the housing. By: 1 the gap between the reversed surfaces of the housing and the piston is filled with liquid, the piston is with channels communicating with the axial orifice and said cavity, axial orifice with gas, and display means in the form of a movable rod with a scale, hermetically mounted in the axial hole of the rod, and a locking pin of the rod fixed on the lid. sixteen W 17